To ensure that you are on course: It is generally good advice to have checkpoints in place.
Hooks and anchors for when you will stop and check: Am I still doing what I set out to do? From which wagons have I fallen and want to get back on to?
In an attempt to be really clever, you may even go as far as to have checkpoints to check that your checkpoints are in place.
It is checkpoints all the way down until you hit turtles and this realisation: Things degenerate. It is what nature does.
The only safe checkpoint to have is this: A promise today, that when you realise you forgot everything that was important to you, you will be kind to yourself.